The Measurement of a New Antimicrobial Quinolone in Hair as an Index of Drug Exposure

The study investigated the presence of the antimicrobial quinolone OPC-17116 in hair as an indicator of drug exposure. Scalp hair samples from healthy male volunteers were analyzed after administering single and repeated doses of the drug. The drug was detectable in hair segments corresponding to the administration period, assuming a growth rate of 1 cm/month. In a separate group, OPC-17116 was administered at 300 mg three times daily for 2 days, and the drug was found in specific hair segments without significant diffusion along the hair shaft. These results suggested that measuring OPC-17116 in hair could serve as a reliable index of drug exposure and a time-marker for analyzing other drugs.